A method of strengthening ancient domes and vaults, and problems of their stress-strain states in seismic regions

Discussed in the present article is an original structure for strengthening ancient stone-built domes, whose seismic resistance is to be enhanced. The solution consists of a thin reinforced concrete shell provided with a support ring and placed above the dome. Connecting members project downwards from the shell and are introduced in the midst of the dome's stone. The resulting reinforcement is achieved by creation of an interconnected stone-reinforced concrete structure. Stress concentrations in the connection areas are a specific problem of the interconnected structures. While said structures are subject to static loads and seismically originated forces, problems are considered relating to the stress-strain state of the stone dome and how its dynamic characteristics are influenced by the number and location of connecting members. Issues of stress concentration located in surrounding connecting members are discussed. The problem under study is considered through an example of a real conservation case involving the ancient stone dome in the town of Ahaltsihe (in the seismic zone of Georgia), and also a dome of the Hagia Sophia type. The stress-strain states are analyzed using the finite element method.